1. Field
The invention is in the field of supports for exterior pipes on building roofs.
2. State of the Art
It is very common in commercial buildings for there to be various types of pipes which are exposed and run along the top of the roofs of such buildings. These pipes may be connected to air conditioning units mounted on a building roof or to various other service units.
It is currently common practice for these pipes to be supported above the roof surface at intervals along their length by placing blocks of wood between the roof surface and the pipes. With temperature changes, the pipes expand and contract and, partly because of the large contact surface area between a block and the pipe, the block moves with the pipe. After a period of time, the movement of the block against the roof with the weight of the pipe thereon causes damage to the roof, which usually results in a leak and requires expensive roof repair. Even where the blocks are nailed down to the roof, the nails and the wood usually deteriorate in a relatively short time period so that the blocks break loose. Further, wood blocks are difficult to seal so the roof usually leaks about these nail holes.
There is currently available a pipe holder which is mounted on a roof and has a shaft mounted pulley or roller on which the pipe rests and rolls as it expands and contracts. While this prevents problems due to contraction and expansion of the pipes, it is necessary that holes be made in the roof for mounting purposes, and the device is expensive. Where many holders are required, they can easily cost more than a number of later roof repairs. Thus, that roller solution to the problem has not achieved a great deal of commercial success.
There has recently been developed an improved pipe-supporting device which has a substantially flat bottomed base with pipe supporting structure rising from the base that substantially equally distributes the weight of the pipe over the bottom of the base and thus over the area of the roof in contact with the base. The pipe supporting structure has a substantially V recess having divergent line contacts for receiving and supporting the pipe above the base. In this manner, the pipe is supported in the V with two contact points. This provides for easy sliding movement of the pipe within the support as the pipe expands or contracts. This pipe supporting device is disclosed in application for U.S. Letters Patent Ser. No. 438,735, filed Nov. 3, 1982, and assigned to the same entity as is this application.
While the pipe-supporting device of the application just referred to is a significant improvement over the prior art, it has been found that the resistance to pipe movement with respect to the supporting device may be further lessened and the device thereby significantly improved by the use of inexpensive plastic rollers which fit into and rotate in receiving troughs.